This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The reason for this research is to develop a model of infection with Campylobacter jejuni, a bacterium that causes food and water-borne disease (mainly diarrhea). The main goal in developing the model is to find a dose of the Campylobacter bacteria that causes diarrhea in about 3 out of 4 volunteers while being done as safely as possible. This information will assist the development of a vaccine against Campylobacter infections. Volunteers will be screened for eligibility within 60 days prior to enrollment. Screening will include obtaining signed informed consent prior to any study procedure. This will be followed by medical history, current medications, and blood samples for safety labs (WBC, HCT, HGB, platelet count;chemistry panel;screening for HIV, HLA-B27, HBV, and HCV;urine pregnancy testing for females). Eligible volunteers will be enrolled and admitted to the GCRC the night before, Day -1. Following challenge ingestion Day 0, the volunteers will have blood drawn to include safety labs and immunologic response, stool specimen collected, weight and tested, review of signs and symptoms, and clinical assessment. solicitation of AEs and documentation of concomitant medications will occur on all inpatient days, Day 0 to Day 9 and on scheduled study days, Day 14 and Day 28. All subjects will receive antibiotics and have two consecutive negative stool cultures within 12 hours to be eligible for discharge. Two outpatient follow up visits on Day 14 and Day 28 with blood drawn to include safety labs and immunologic response and There will be a 6 month phone assessment to check status of volunteers. The first DSMB meeting is planned, to occur after each cohort has completed the inpatient phase. An assessment regarding the safety of the dose level and determine if the next cohort should continue at the next higher dose. The main goal of this early assessment is to review safety data. DSMB meetings may also be called on an ad hoc basis when deemed necessary.